Nonsonorous detachable bush connection for sound conduits



Jan. 922, 1929. 1,699,586

E. A. GRAHAM NONSONOROUS DETACHABLE BUSH CONNECTION FOR SOUND CONDUITS Filed Feb. 5, 1926 Patented Jan. 22, 1929.

I C E EDWARD ALFRED GRAHAM, OF BROCKLEY, GRAHAM, EXECUTORS OF SAID EDW NONSONOROUS DETACHABLE BUSH CONNECTION ENGLAND; MARIA GRAHAM AN D ALFRED ARD ALFRED GRAHAM, DECEASED.

FOR SOUND CONDUITS.

Application filed February 5, 1926, Serial No. 86,211, and in Great Britain June 17, 1925.

In the specification of British Letters Patent No. 191,801 granted to me, I have de scribed means whereby parasitic resonant vibrations, set up in sound transmitting or receiving systems comprising sound-receiving or collecting trumpets for telephonic transmitters and like sound-emitting trumpets, horns or conduits for telephonic receivers, can effectively be absorbed. For this purpose,.the means employed consisted of a tubular cushion or bush of sound absorbing,

sound insulating or non-sonorous material such as rubber, cork or the like, arranged between the smaller end of the trumpet, horn or conduit and a sound intake or exit tube or nozzle on the telephonic transmitter or receiver. I

The present invention has for its principal object to provide-an improved construction for a non-sonorous bush connection of the general type described and claimed in the said former specificationand which is applicable to all types of acoustic transmitting, receiving or reproducing'apparatus.

In the drawings constituting part of the said specification, thereis illustrated one construction-of such a tubular bush comprising a plane cylindrical portion flanged at one end and arranged between the sound emission nozzle of a telephonic instrument and the constricted end of a sound conduit which may be the mouth piece or sound receiving or collecting trumpet for a telephonic transmitter, or the sound emitting trumpet or horn for a telephonic receiver. In those instances where a trumpet or the like (hereinafter re- 7 ferred to generically as a sound conduit) is supported by and above a telephonic transmitter or receiver (hereinafter referred to as the telephonic unit) in a vertical plane, or where the telephonic unit is held in a substantially horizontal plane by a sound-conduit which is itself supported there is little likelihood of the telephonic unit accidently becoming detached from the sound conduit but should it be required to suspend the said sound conduit in a vertical plane with its constricted end, carrying the telephonic receiver, pointing in a downward direction, there is possibility of the telephonic unit becoming detached from the constricted end of the sound conduit with disadvantageous results.

In order to avoid the disadvantage men tioned, the tubular cushion of sound insulating, sound-absorbing or non-sonorous materlal such as rubber, rubber sponge, cork or the like, the inlet or exit nozzle of a sound receiving or emitting unit (hereinafter conveniently referred to the small end of the sound conduit, between which small end and the nozzle the said cushion is interposed after the fashion of a bush, are, according to the present invention, adapted to admit of the parts being interlocked with one another in such a manner that they cannot become accidentally detached from one another but so as to admit of the sound conduit being readily removed from the telephonic unit, or of the telephonic unit being readily removed fromthe sound conduit by hand when desired. Such a jointing of the parts may be effected by forming some or all of the parts with corresponding screw threads. v

In the accompanying drawings, Figs. 1 to 1, are vertical sections showing various jointing arrangements for connecting a telephonic unit to a sound conduit according to the invention, Fig.1 being partly in elevation.

In Fig. 1, the nozzle a on the cover Z) of the sound receiving or emitting unit, for instance a telephonic receiver, is formed with corrugations or an external screw thread and the tubular cushion or bush 0, made of rubber or other material of the kind hereinbefore referred to, is formed internally with corrugations or a screw thread to fit the nozzle and externally with a convex surface to fit a corresponding concave surface within a socket (Z forming an extension of the sound conduit (Z. The socket holds the cushion firmly in position when detached from the nozzle.

In Fig. 2, the tubular cushion 0 is held within a nozzle a of a telephonic unit which is formed internally with a concave surface to fit the convex surface of the cushion, and its internal corrugations or screw thread is adapted to engage a corrugated or screw threaded end d of the sound conduit (Z.

In Fig. 3, the tubular cushion 0 is corrugated or screw threaded both externally and internally to engage with correspondingly corrugated or screw threaded portions of the nozzle a and sound conduit.

The tubular cushion 0 in Figs. 1 and 2, can be placed in position by first deforming it, placing it in position and then allowing it to expand. Or the internal surface of the as a telephonic unit) and cushion and nozzle in Fig.

constricted end of the sound conduit and producing apparatus,

recess inthe extension (Z of the sound conduit (Z (Fig. 1), or of the nozzle a (Fig. 2), may be cylindrical and the adjacent surface of the cushion 0 be also of cylindrical shape and adapted to fit it, as shown for example in Fi l in connection with a nozzle, the nozzle (4 being provided with an inwardly projecting flange a to prevent accidental removal of the cushion c.

The engaging V corrugations or screw threads may be of parallel or taper shape. They are shown as of varying or taper shape in the examples, except those'between the 3 and between the cushion in Fig. i where they are of parallel shape.

-The tubular cushion may be firmly fixed within the extension (Z of the sound conduit (Fig. 1), or within the nozzle 64 (Figs. 2 and 4) by an adhesive, or by vulcanization when it is of rubber.

lVhat I claim'is 1. In sound transmitting, receiving or rethe combination with a cover member for the sound transmitting, receiving or reproducing element, said cover member having a tubular sound conveying nozzle, of a tapering sound conduit having its restrictedend arranged in substantially concentric overlapping'relationto said nozzle, and a tubular cushioning member constituted as a connecting bush between the overlapping parts of the nozzle and sound conduit, the companion surfaces of the interengaged tubular parts being shaped so that the said parts can be readily interlocked with one another against accidental detachment by direct axial movement of any of the parts though free to the outer surface of'the nozzle formed be purposely separated by hand when desired by rotary movement.

2. In sound transmitting, receiving or reproducing apparatus, a cover member having a sound conveying nozzle, a tapering Sound conduit betweenwhich and the nozzle there is an overlap and a tubular cushion interposed between overlapping parts of said nozzle and said sound conduit, said cushion being incapable of direct axial movement in relation to either of said overlapping portions of said nozzle and conduit but movable, with one of said two overlapped elements and being formed with a screw thread andadapted by rotation to be removably engaged with the other of saidelements.

3. In sound transmitting, receiving or reproducing apparatus, a cover member having a male nozzle, an associated tapering sound conduit having a socket at the smaller end adapted to surround said nozzle and a tubular cushion fixed within the socket, the inner surface of the cushion being screw threaded and with a corresponding screw thread.

4. In sound transmitting, receiving or re producing apparatus a cover member having an externally screw threaded nozzle, an associated tapering sound conduit having a socket the wall of which in cross section is concave interiorly anda tubular cushion screw threaded internally to receive the externally screw threaded nozzle and to fit the socket, said cushion being immovable in relation to the socket, substantially as described.

Signed at London, day of January, 1926.

EDWARD ALFRED GRAHAM.

England, this eleventh 

